MLECO-2138: Fix line feeding with GCC

Signed-off-by: George Gekov <george.gekov@arm.com>
Change-Id: I32c05897085554f469bedc55e4e2800788121c55
diff --git a/source/use_case/ad/src/MainLoop.cc b/source/use_case/ad/src/MainLoop.cc
index 6431509..3c2f9cc 100644
--- a/source/use_case/ad/src/MainLoop.cc
+++ b/source/use_case/ad/src/MainLoop.cc
@@ -40,6 +40,7 @@
     printf("  %u. Show NN model info\n", MENU_OPT_SHOW_MODEL_INFO);
     printf("  %u. List audio signals\n\n", MENU_OPT_LIST_AUDIO_CLIPS);
     printf("  Choice: ");
+    fflush(stdout);
 }